The idea of using phages for treatment of infectious diseases was initially proposed by d'Herelle in 1917. In the 1920s, the discovery of bacteriophages was thought to be the answer for treatment of bacterial infections. Bacteriophages invade and destroy bacteria and appeared to be the selective therapeutic bullet that would knock out bacteria invading an animal or plant host. Unfortunately, the phages were not as effective in killing bacteria in host organisms as they were in killing bacteria in vitro. The development of antibiotics in the 1940s as the preferred treatment for bacterial infections led to a decline in research into use of bacteriophages for treatments of infectious diseases.
In a few countries, notably in Eastern Europe and India, research continued in the use of bacteriophages and bacterial lysates for treatment of infectious diseases and enhancement of immune responses. Though much of that research is still not accepted widely in other industrialized countries, a renewed interest in this research is growing as a result of the occurrence of antibiotic resistant bacteria. Many infectious diseases that were once easily treatable with antibiotics are now a serious health threat because the bacteria are resistant to most, if not all, antibiotics. Medical science is searching for treatments that can respond to these resistant bacteria in a way that does not lead to even more resistant infectious strains.
The U.S. Centers for Disease Control and Prevention estimates that 20% to 50% of prescribed antibiotics are unnecessary. The overuse of antibiotics in medicine and agriculture has greatly fostered the development of resistant strains of bacteria. In a microenvironment bombarded with antibiotics, the few bacteria that can resist the drugs proliferate. Bacteria are becoming increasingly resistant to what were previously considered “last resort” antibiotics.
Bacteriophage therapy has not gained much attention or acceptance in most industrialized countries, in part due to the reliance on pharmaceuticals, such as antibiotic treatment for bacterial infections. With the advent of increased bacterial resistance, bacteriophage therapy has come under renewed scrutiny as a possible alternative to pharmaceutical treatments of bacterial infections. What is needed are compositions and methods for treatment and prevention of microbial infections that do not rely on pharmaceutical antibiotic therapies. Such methods and compositions should be capable of treating or preventing infections in organisms, including humans, animals and plants.